JP6620438B2 - Low adsorptive coextrusion multilayer sealant film - Google Patents

Description

The present invention relates to a low adsorptive sealant film in which the amount of adsorbing aromatic components and medicinal components in the contents is reduced, a packaging material using the same, and a packaging bag and packaging container comprising the same.
More specifically, since the amount of organic compounds adsorbed in the content is reduced, the sealant film is excellent in maintaining the quality of the content and excellent in heat sealability and film forming stability, and packaging using the same. The present invention relates to a material, and a packaging bag and a packaging container made of the material.

In packaging containers such as foods and pharmaceuticals, the phenomenon that organic compounds such as medicinal components in the contents are adsorbed or sorbed on the sealant film that is the innermost layer of the packaging bag or packaging container has been a problem. . On the other hand, in anticipation of the amount adsorbed or sorbed on the sealant film, measures are taken to contain an excessive amount of medicinal ingredients in the contents. However, when a medicinal component or the like is expensive, an excessive amount of blending increases the cost, which is not preferable.
In addition, for example, in the packaging of luxury goods, the fragrance component is adsorbed or sorbed on the sealant film, so that the fragrance at the time of filling cannot be maintained until the product reaches the consumer or until the expiration date. There is.

  Furthermore, the sealant film used for packaging foods and beverages has strength, sterilization resistance and heat resistance for protecting the contents from distribution, storage or sterilization treatment, transparency for confirming the contents, Various functions such as heat sealability for sealing the container are required, and for satisfying these requirements, for example, an unstretched polyolefin-based resin film is used. This sealant film is as described above. In addition, it is known that organic compound components in the contents are easily adsorbed or sorbed.

  In order to solve these problems, sealant films made of a polyester resin, amorphous polyethylene terephthalate (PET), polyacrylonitrile resin, or the like have been proposed (Patent Documents 1 and 2). However, since the polyester-based resin has poor heat-sealability and a seal failure is likely to occur during box making, a packaging container having a sealant layer made of this has a drawback that the contents leak. In addition, amorphous PET cannot obtain a sufficient sealing strength and cannot be used for packaging heavy objects. On the other hand, the polyacrylonitrile resin is expensive and it is difficult to obtain materials, and further, it is difficult to form a film for forming a film.

JP-A-5-162737 JP-A-8-143453

  The present invention solves the above-mentioned problems, has sufficient sealing strength, is excellent in film forming stability and processability, and maintains various functions required for conventional sealant films. It is an object of the present invention to provide a sealant film that hardly adsorbs an organic compound, that is, excellent in low adsorptivity, a packaging material using the same, and a packaging bag and a packaging container comprising the same.

  As a result of various studies, the inventor has adjoined the outer layer, the first low-adsorption resin layer, the anti-curl layer, the second low-adsorption resin layer, and the inner layer in contact with the contents in this order. A low adsorptive coextruded multilayer sealant film, wherein the outer layer is a layer made of linear low density polyethylene (LLDPE) or high pressure process low density polyethylene (LDPE), and the anti-curl layer and the inner layer are LLDPE The first and second low adsorptive resin layers are layers made of a resin composition containing 80 to 97% by mass of cyclic olefin copolymer (COC) and 3 to 20% by mass of LDPE. The COC is a copolymer obtained by copolymerizing 55 to 85% by mass of a norbornene monomer and 15 to 45% by mass of an α-olefin, and the low adsorptive coextruded multilayer sealant film, and Packaging material using the same, and packaging bags and packaging containers made of it was found to achieve the above object.

The present invention is characterized by the following points.
(1) A low-adsorption coextrusion multilayer having 5 layers of an outer layer, a first low-adsorption resin layer, an anti-curl layer, a second low-adsorption resin layer, and an inner layer in contact with the contents in this order. A sealant film, wherein the outer layer is a layer made of LLDPE or LDPE, the anti-curl layer and the inner layer are layers made of LLDPE, and the first and second low adsorptive resin layers are 80 to It is a layer comprising a resin composition comprising 97% by mass of COC and 3-20% by mass of LDPE, and the COC comprises 55-85% by mass of norbornene monomer and 15-45% by mass of α- The low adsorptive coextruded multilayer sealant film, which is a copolymer obtained by copolymerizing an olefin.
(2) The total thickness of the first and second low adsorptive resin layers is in the range of 7 to 33% of the total thickness of the low adsorptive coextruded multilayer sealant film, as described in (1) above. Low adsorptive coextrusion multilayer sealant film.
(3) The low adsorptive coextruded multilayer sealant film according to (1) or (2), wherein the total thickness is 20 to 150 μm.
(4) The low adsorptive coextrusion multilayer sealant film according to any one of (1) to (3), wherein the outer layer is a layer made of LLDPE.
(5) The low adsorptive coextrusion multilayer sealant film according to any one of (1) to (4), wherein the inner layer contains an antiblocking agent.
(6) The low adsorptive coextruded multilayer sealant film according to any one of (1) to (5), wherein the glass transition temperature of the COC is 100 ° C. or lower.
(7) A packaging material obtained by laminating a substrate on the outer layer side surface of the low adsorptive coextruded multilayer sealant film according to any one of (1) to (6).
(8) A packaging bag obtained by superposing and packaging the packaging material according to (7) so that the inner layer of the low-adsorption coextrusion multilayer sealant film becomes a contact layer.
(9) A liquid paper container obtained by superposing and packaging the packaging material according to (7) so that the inner layer of the low-adsorption coextrusion multilayer sealant film becomes a contact layer.

  The sealant film of the present invention is a five-layer coextrusion multilayer film obtained by alternately laminating layers made of LLDPE or LDPE and layers made of a resin composition obtained by blending COC and LDPE.

  In general, it is known that a cyclic olefin-based resin such as COC has a high intermolecular force during melt film formation and causes aggregation between polymers. As a result, fish eyes are formed due to the aggregation of the resin throughout the film, and it is difficult to obtain a uniform film surface. These tendencies become more prominent during film formation by the inflation method, and the COC film obtained by the method generates innumerable fish eyes on the entire surface. Further, the COC film has high rigidity and lacks processability as a film.

However, by blending LDPE with COC, among other polyethylenes, according to the present invention, gelation of COC can be prevented and fish eye formation can be suppressed. Further, by further laminating a layer made of a resin composition obtained by blending COC and LDPE and a layer made of LLDPE or LDPE and co-extrusion forming, a higher fish eye suppression effect can be obtained. Therefore, the sealant film of the present invention is easy to form, and can form a beautiful layer that is homogeneous and has good transparency. In addition, the generation of fish eyes can be suppressed during high-speed film formation by the inflation method.

In such a sealant film of the present invention, the layer made of the resin composition containing COC and LDPE forms a dense surface structure with a close intermolecular distance based on the high intermolecular force of COC. Moreover, the layer which consists of LLDPE or LDPE exhibits the high interlayer adhesiveness with the layer which consists of this resin composition, and has provided favorable film forming stability. The sealant film of the present invention having such a structure hardly adsorbs components in the contents, that is, has excellent low adsorptivity.
In addition, the sealant film of the present invention retains good heat sealability and suitable flexibility, is easy to process, has excellent curability and is easy to handle, and can be used during heat sealing at low temperatures. Demonstrates sufficient seal strength during box making.

It is a schematic sectional drawing which shows the sealant film of this invention. It is a schematic sectional drawing which shows the example about the layer structure of the packaging material using the sealant film of this invention.

The above-described present invention will be described in more detail below.
<1> Layer structure of sealant film of the present invention and packaging material using the same FIG. 1 is a schematic cross-sectional view showing the sealant film of the present invention.
FIG. 2 is a schematic cross-sectional view showing an example of the layer structure of a packaging material using the sealant film of the present invention.

As shown in FIG. 1, the sealant film of the present invention comprises an outer layer (1), a first low-adsorption resin layer (2), an anti-curl layer (3), and a second low-adsorption resin layer (4). And a co-extruded multilayer sealant film (14) consisting of 5 layers in which the inner layer (5) in contact with the contents is provided in this order.
Here, the outer layer (1) is a layer made of LLDPE or LDPE, the anti-curl layer (3) and the inner layer (5) are layers made of LLDPE, and the first and second low adsorptive resins sandwiched between them. The layers (2, 4) are layers made of a resin composition containing COC and LDPE. The LLDPE forming the inner layer (5) may contain a small amount of an anti-blocking agent, for example, less than 20% by mass, in order to improve the slippage of the film surface and improve the processability.
Arbitrary base materials, such as a base material layer (10) and / or a barrier layer (12), are provided on the outer layer (1) side surface of the sealant film (14) of the present invention via an adhesive layer (11, 13). By laminating, the packaging material of the present invention is obtained. The lamination means may be any method such as sandwich lamination or dry lamination.

  Hereinafter, the resin names used in the present invention are those commonly used in the industry. In the present invention, the density conforms to JIS K7112.

<2> Sealant film In the five-layer coextruded multilayer sealant film of the present invention, the total thickness and the thickness of each layer can be appropriately set according to the application of the packaging material to be applied. The total thickness is 20 to 150 μm, more preferably 30 to 60 μm, in order to obtain the necessary sealing strength for the bag and from the viewpoint of stable film formation, low adsorptivity and product cost. The rigidity of the film is increased to cause molding failure, and if it is thinner than this, sufficient adhesive strength cannot be obtained, and the sealing performance of the packaging container can be impaired.

  The total thickness of the first and second low-adsorbent resin layers is 7 to 33% of the total thickness of the sealant film, and more preferably 15 to 25%. When the total of the low adsorptive resin layers is thinner than 7% of the total thickness, it is difficult to obtain sufficient low adsorptivity. Conversely, if it is thicker than 33%, the low adsorptivity increases, but the flexibility and heat sealability of the film may be impaired.

  Each of the first and second low adsorptive resin layers is preferably at least 3 μm or more, for example, 3 to 7 μm. Since the low adsorptive resin layer is divided into two layers with the anti-curl layer interposed therebetween, the sealant film of the present invention can have both excellent low adsorptivity, flexibility and film formation stability. Further, by making the front and back of the film symmetrical, it is possible to prevent the film from curling on either side.

(I) Outer layer In the sealant film of the present invention, the outer layer is located on the surface of the sealant film, forms a bonding surface with the base material, and is formed adjacent to the first low-adsorbent resin layer. It is a layer that supplements stability.
When laminating with a base material, a particularly high interlayer adhesion strength is obtained during sandwich lamination by melt extrusion, and since the film forming stability of COC is improved, LLDPE and LDPE are used as resins constituting the outer layer. Are used, more preferably LLDPE. If necessary, conventional additives such as antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, flame retardants, and colorants may be added.
The thickness of the outer layer is preferably 10 to 20 μm, and if it is too thin, sufficient interlayer adhesion strength with the substrate cannot be secured, and if it is too thick, the thickness of the inner layer cannot be balanced, and the film is formed after film formation. Tends to curl to either side.

Hereinafter, in the present invention, LLDPE is a linear polyethylene having a density of 0.900 to 0.940 g / cm ³ , and uses a single site catalyst such as a metallocene catalyst or a multisite catalyst such as a Ziegler-Natta catalyst. And a copolymer obtained by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms at low temperature and low pressure. Specific examples of the α-olefin having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-nonene and 1-decene. , 1-dodecene and the like. Examples of the copolymerization method include ethylene and α-olefin polymerization methods such as a low pressure method, a slurry method, a solution method, and a gas phase method.

The LLDPE of the present invention has 3 to 25 short chain branches per 1000 carbon atoms as short chain branches, but is not distinguished from LDPE in that it does not have long chain branches exceeding about 20 carbon atoms. Usually, in LLDPE, the structural unit derived from ethylene is about 99.9 to 90 mol%, and the structural unit derived from α-olefin is about 0.1 to 10 mol%. In the present invention, LLDPE prepared with a metallocene catalyst can be suitably used because of excellent structural uniformity.
Examples of LLDPE suitable for use in the present invention include “Evolue ^(R) ” manufactured by Prime Polymer Co., Ltd.
On the other hand, LDPE is an ethylene homopolymer produced by a high pressure method and having a density of 0.910 or more and less than 0.930. Examples of LDPE suitable for use in the present invention include “Sumikasen ^(R) ” manufactured by Sumitomo Chemical Co., Ltd.

(Ii) First low adsorptive resin layer The first low adsorptive resin layer is located between the outer layer and the anti-curl layer, and prevents penetration, adsorption and sorption of organic compounds in the contents. It consists of a resin composition containing COC and LDPE. If necessary, conventional additives such as antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, flame retardants, and colorants may be added.
In a preferred embodiment of the present invention, COC is a copolymer obtained by copolymerizing a norbornene monomer and an α-olefin.

The norbornene monomer has a bicyclo [2.2.1] hept-2-ene (norbornene) skeleton, specifically, bicyclo [2.2.1] hept-2-ene and its derivatives, tricyclo [4.3.0.1 ^2.5] -3- decene and derivatives thereof, tricyclo [4.4.0.1 ^2.5] -3- undecene and derivatives thereof, tetracyclo [4.4.0.1 ^2.5 .1 ^7.10] -3-dodecene and derivatives thereof, pentacyclo ^{[6.5.1.1 3.6 .0 2.7 .0 9.13]} -4- pentadecene and its derivatives, pentacyclo [7.4.0.1 ^2.5 .1 ^9.12 .0 ^8.13] -3-pentadecene and its derivatives, pentacyclo ^{[6.5.1.1 3.6 .0 2.7 .0 9.13]} -4,10- penta decadiene and its derivatives, pentacyclo [8.4.0.1 ^2.5 .1 ^9.12 .0 ^8.13] -3-hexadecene and derivatives thereof, and the like, et al. However, it is not limited to these. These cyclic olefins may have a polar group such as an ester group, a carboxyl group, and a carboxylic anhydride group as a substituent.

  As the α-olefin copolymerized with the norbornene monomer, ethylene and an α-olefin having 3 to 20 carbon atoms can be used. Specifically, ethylene, propylene, 1-butene, 1-pentene. , 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene and the like, preferably ethylene.

In the present invention, COC is produced by randomly using 15 to 45% by mass of an α-olefin and 55 to 85% by mass of a norbornene monomer using a single site catalyst such as a metallocene catalyst or a multisite catalyst. This is done by polymerizing. The copolymer copolymerized at this ratio can achieve both excellent low adsorptivity and flexibility by forming a film according to the present invention. In addition, it has low water absorption, has a barrier property against water vapor, has low birefringence, and has excellent optical properties, and therefore has excellent transparency. Furthermore, it exhibits good heat resistance and dimensional stability.
Preferably, it is preferable to use COC having a glass transition temperature of 100 ° C. or lower, more preferably 85 ° C. or lower. By using COC having a low glass transition temperature, generation of wrinkles can be prevented during film formation, and film formation stability is improved.

Examples of the COC preferably used in the present invention include “TOPAS ^(R) ” manufactured by Polyplastics Co., Ltd.
By blending LDPE with the above-mentioned COC, it is possible to prevent the generation of fish eyes due to aggregation of COCs during film formation particularly preferably as compared with the case of blending other polyethylene.
As a blend amount of LDPE, it blends in the resin composition which comprises a low adsorptivity resin layer in the ratio of 3-20 mass%, for example in the ratio of 3-10 mass%. If the ratio of LDPE is too large, the low adsorptivity may be impaired. In addition, the film forming stability is lowered, and wrinkles are easily generated. On the other hand, when the ratio of LDPE is too small, the film-forming stability is impaired and fish eyes are likely to be generated.

In a preferred embodiment of the present invention, the LDPE has a melt flow rate (MFR) at 190 ° C. of 10 to 80 g / 10 minutes, particularly 15 g / 10 minutes or more, more preferably 20 g / 10 minutes or more, for example 25 to 25 g. The thing of 80 g / 10min can be used especially suitably. LDPE having an MFR in this range can be blended homogeneously with COC to further improve film formation stability. In the present invention, the melt flow rate is measured according to JIS-K-7210 (190 ° C., load 2.16 kg).

(Iii) Anti-curl layer The anti-curl layer is located between the two low-adsorptive resin layers, supplements these film-forming stability, adjusts the thickness of the film, imparts flexibility, and further It is a layer that prevents the film from curling to either side after film formation by adjusting the front and back of the film to be symmetrical or substantially symmetrical.
In order to fulfill these functions, LLDPE can be suitably used as the resin constituting the anti-curl layer, and if necessary, an antioxidant, an ultraviolet absorber, a light stabilizer, an antistatic agent, a flame retardant Conventional additives such as coloring agents and coloring agents may be added.
The thickness of the anti-curl layer is preferably 5 to 20 μm. If the anti-curl layer is too thin, film forming stability and film flexibility during coextrusion film formation may be impaired. Conversely, if the anti-curl layer is too thick, the low adsorptivity is impaired, which is not preferable.

(Iv) Second low adsorptive resin layer The second low adsorptive resin layer is located between the anti-curl layer and the inner layer, and prevents penetration, adsorption and sorption of organic compounds in the contents. The second layer is made of a resin composition containing COC and LDPE, like the first low-adsorption resin layer. If necessary, conventional additives such as antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, flame retardants, and colorants may be added.
By providing the low-adsorbent resin layer in two thin layers in the sealant film, the flexibility can be maintained while maintaining the excellent low-adsorbability compared to providing one low-adsorbent resin layer of double thickness. Increases the processability.

(V) Inner layer The inner layer is located on the surface of the sealant film and is the innermost layer that comes into contact with the contents during box making, and is a layer that is adjacent to the second low adsorptive resin layer and supplements its film-forming stability. is there.
As the resin constituting the inner layer, LLDPE can be suitably used because it has excellent film-forming stability and low-temperature sealability, and good seal strength can be obtained. If necessary, an antioxidant, an ultraviolet absorber, Conventional additives such as a light stabilizer, an antistatic agent, a flame retardant, and a colorant may be added.
The thickness of the inner layer is preferably 5 to 15 μm. If the inner layer is too thin, sufficient sealing strength cannot be obtained and the sealing performance is impaired. On the contrary, if the inner layer is too thick, the amount of the organic compound adsorbed in the contents increases and the low adsorptivity is impaired.
The inner layer may contain an inorganic filler as an antiblocking agent in order to improve the slipperiness during processing. When the inner layer contains an antiblocking agent in advance, it can also be suitably applied as a liquid packaging container in which a lubricant cannot be sprayed later.

The addition amount of the inorganic filler is 0.5 to 20% by mass, preferably about 5.0 to 15% by mass with respect to the inner layer. When the added amount of the inorganic filler is smaller than this, the filler is hardly exposed on the surface of the sealant film, and the effect of improving the slip failure is small. Moreover, since it will be in a saturated state on the sealant film surface when it exceeds 20 mass%, even if it adds more fillers, the effect corresponding to this cost is not acquired. Further, the transparency is remarkably lowered and the visibility is deteriorated. The inorganic filler can be homogeneously dispersed in the LLDPE by blending as a master batch.
Suitable inorganic fillers which can be _{used, SiO 2, AL 2 O 3} , TiO 2, ZnO, Fe 2 O 3, SnO 2, CeO 2, NiO, PbO, S 2 Cl 2, ZnCl 2, FeCl 2, CaCO ₃ , B ₂ O _{3 and the} like, and a filler having an average particle diameter of 2 to 15 μm can be used. Preferably, a silicon oxide SiO ₂ filler is used. When the average particle size of the inorganic filler is less than 2 μm, there is no effect in improving the slipperiness, and when the average particle size exceeds 15 μm,
The container surface may be rubbed and damaged by the inorganic filler protruding on the surface of the film-forming film. In addition, in this invention, an average particle diameter means the particle size of the particle which exists most by particle size distribution measurement. The particle size distribution can be measured by a Coulter counter method.

(Vi) Manufacturing method of sealant film In this invention, a sealant film is formed into a film by the co-extrusion method using resin and resin composition which comprise each layer. By forming a film by the coextrusion method, high interlayer adhesion and film forming stability can be obtained, low adsorptivity can be improved, and a beautiful film can be obtained. In particular, the generation of fish eyes can be suppressed. In particular, the sealant film can also be formed by a coextrusion inflation method. By forming a film by the coextrusion inflation method, film formation can be performed at a low temperature, and troubles caused by resin odor due to heating are reduced.

<3> Packaging material A low adsorptive packaging material is obtained by laminating the sealant film of the present invention so that the inner layer is the innermost layer with the surface on the outer layer side facing an arbitrary substrate.
As a base material used here, arbitrary films, such as paper, a base film, or the barrier film which provided the gas barrier layer on the base film, can be used.
As the paper, any paper having various formability, bending resistance, rigidity, waist, strength and the like can be used depending on the application of the paper container to be applied. For example, it is a main strength material, and various types of paper such as strong sized bleached or unbleached paper, or pure white roll paper, kraft paper, paperboard, processed paper, and milk base paper can be used.
As a base film, a biaxially stretched film of polyester such as PET and polyethylene naphthalate, a biaxially stretched film of polyamide such as nylon 6, nylon 66, MXD6 (polymetaxylylene adipamide), a biaxially stretched polypropylene film, etc. The plastic film can be suitably used. These may be used singly or may be used by combining a plurality.

The gas barrier layer may be a vapor deposition layer of an inorganic oxide such as silica, alumina, zinc oxide, magnesium oxide, indium tin oxide, or a metal such as aluminum. Or ethylene / vinyl acetate copolymer saponified product (EVOH), polyvinylidene chloride (PVDC), nylon MXD6, etc., metal film such as aluminum foil, or PVDC, polyvinyl alcohol (PVA), polyacrylic acid A gas barrier film such as a biaxially stretched nylon film (ON film), a biaxially stretched PET film, or a biaxially stretched polypropylene film (OPP film) provided with a coating layer such as (PAA) is formed on a substrate via an adhesive layer. It may be laminated on a film.
As a method for laminating the gas barrier layer, when the gas barrier layer is a vapor deposition layer, the gas barrier layer is laminated on the base film by an arbitrary vapor deposition method such as a chemical vapor deposition method and a physical vapor deposition method. When a gas barrier layer is a gas barrier film, it laminates | stacks on a base film through an adhesive bond layer.

Lamination of the sealant film of the present invention and the substrate can be performed by a conventional means such as a dry laminating method or a sandwich laminating method via an arbitrary adhesive or adhesive resin. As needed, you may perform various surface pretreatments, such as providing an anchor-coat agent layer in the bonding surface of a base material, before laminating | stacking.
In a particularly preferred embodiment of the present invention, by laminating a sealant film and a substrate by a sandwich lamination method using molten polyethylene as an adhesive layer, high interlayer adhesive strength can be obtained and delamination can be prevented.

<4> Packaging Container The packaging material of the present invention can be suitably used as a packaging bag or packaging container, particularly for forming a packaging bag or packaging container that requires the quality retention of the contents. Moreover, since the sealant film of the present invention exhibits a low sealing property and a high sealing strength, it can also be used as a paper container, particularly a liquid paper container.

The production of the packaging bag from the packaging material of the present invention can be made by folding the packaging material described above in two or by preparing two packaging materials, with the surfaces of the sealant films facing each other, and further surrounding the peripheral edge portion. For example, side seal type, two-side seal type, three-side seal type, four-side seal type, envelope-attached seal type, joint-attached seal type (pillow seal type), pleated seal type, flat bottom seal type, square bottom seal type, gusset It can be manufactured as a packaging bag of various forms by heat-sealing with a heat-sealing form such as a mold.
In the above, as a heat sealing method, for example, a known method such as a bar seal, a rotary roll seal, a belt seal, an impulse seal, a high frequency seal, and an ultrasonic seal can be used.

Or manufacture of the paper container from the packaging material of this invention is normally performed as follows. That is, after printing as necessary on the surface of the packaging material of the present invention, it is punched out, and the end face is skived and hemmed so that the contents do not come into contact with the end face. Heat seal by heating, flame heating, etc. to make a paper container.
The shape of the paper container may be determined as appropriate according to the use and purpose, and examples thereof include a gable top type, a brick type, a flat type, and a cylindrical paper such as a rectangular container or a round shape. A can etc. are mentioned. For example, a polyethylene cap, a pull tab-type opening mechanism, and the like may be appropriately provided at the spout of the paper container.
The contents filled in the packaging bag or packaging container are not particularly limited, and even if it is solid or gelled, it can be a liquid, for example, various drinks such as liquor, juice such as fruit juice, mineral water, Liquid seasonings such as soy sauce, sauces and soups, or various liquid foods and drinks such as curry, stew and soup, edible oils, machine oils, adhesives, adhesives, and other chemicals, cosmetics, pharmaceuticals and other general goods In addition, chemical products such as shampoos, rinses and detergents may be used.

The packaging bag or packaging container of the present invention can maintain the quality and flavor of the contents over a long period of time and exhibits high sealing performance. Therefore, it is particularly suitably used for packaging foods in which flavor is important, for example, foods such as coffee beans, instant coffee powder, black tea, and green tea. According to the packaging bag of the present invention, the amount of flavor adsorbed on the contents is greatly reduced, and the scent at the time of filling can be maintained for a long period of time.
Next, the present invention will be specifically described with reference to examples.

[Example 1]
(1) As a resin composition constituting the first and second low adsorptive resin layers, COC (TOPAS ^(R) 8007F-600 manufactured by Polyplastics Co., Ltd., a content of norbornene-derived repeating units of 65% by mass, The resin composition was sufficiently kneaded with 95% by mass of glass transition temperature 80 ° C.) and 5% by mass of LDPE (Suntech M6545 manufactured by Asahi Kasei Chemicals Corporation, MFR 45.0 g / 10 min, density 0.915 g / cm ³ ). A product was prepared.
(2) As a resin constituting the inner layer, LLDPE (Ube Maruzen Polyethylene Co., Ltd. Umerit ^(R) 0520F, MFR 2 g / 10 min, density 0.904 g / cm ³ ), antiblocking agent master batch (Sumitomo Chemical Co., Ltd.) ), EMB-21, MFR 4 g / 10 min, containing synthetic zeolite) and mixed so that the inorganic filler was 10% by mass.
(3) As a resin constituting the outer layer and the anti-curl layer, LLDPE (Ultzex ^(R) UZ-1520, MFR 2.3 g / 10 min, density 0.914 g / cm ³ , manufactured by Prime Polymer Co., Ltd.) was prepared. .
(4) Using the resin and resin composition prepared in (1) to (3) above, an outer layer of 15.5 μm / first low adsorptive resin layer by a five-layer coextrusion film forming method using an inflation method A low adsorptive sealant film (thickness 40 μm) of the present invention having a layer structure of 5 μm / anti-curl layer 7.5 μm / second low adsorptive resin layer 5 μm / inner layer 7 μm was produced. In the description of the laminate in the present specification, “/” indicates that the left and right layers are laminated and integrated.
The obtained low adsorptive sealant film had a beautiful film surface without fish eyes, was highly flexible, did not cause curling, and was excellent in handleability and processability.

[Example 2]
Example 1 except that a blend of 97% by mass of COC (TOPAS 8007F-600) and 3% by mass of LDPE (Suntech M6545) was used as the resin composition constituting the first and second low-adsorption resin layers. The low adsorptive sealant film of the present invention was produced in the same manner as described above.
The obtained low adsorptive sealant film had a beautiful film surface without fish eyes, was highly flexible, did not cause curling, and was excellent in handleability and processability.

[Example 3]
Example 1 except that a blend of 90% by mass of COC (TOPAS 8007F-600) and 10% by mass of LDPE (Suntech M6545) was used as the resin composition constituting the first and second low-adsorption resin layers. The low adsorptive sealant film of the present invention was produced in the same manner as described above.
The obtained low adsorptive sealant film had a beautiful film surface without fish eyes, was highly flexible, did not cause curling, and was excellent in handleability and processability.

[Example 4]
Example 1 except that a blend of 80% by mass of COC (TOPAS 8007F-600) and 20% by mass of LDPE (Suntech M65545) was used as the resin composition constituting the first and second low-adsorption resin layers. The low adsorptive sealant film of the present invention was produced in the same manner as described above.
The obtained low adsorptive sealant film had a beautiful film surface without fish eyes, was highly flexible, did not cause curling, and was excellent in handleability and processability.

[Example 5]
A biaxially stretched PET film having a thickness of 12 μm was used as a substrate, a printing layer was provided on one surface, and an anchor coating agent was applied thereon. Subsequently, the application surface of this anchor coating agent and the vapor deposition surface of a transparent vapor deposition film (VMPET, a transparent vapor deposition film in which aluminum oxide is vapor-deposited on one side of a biaxially stretched PET film having a thickness of 12 μm) are made into a polyethylene resin (thickness). 15 [mu] m).
The outer layer side of the low adsorptive sealant film produced in Example 1 above was applied by sandwich lamination using a polyethylene resin (thickness: 15 μm) by applying an anchor coating agent to the surface of the obtained laminated film on the transparent vapor deposition film side. The packaging materials of the present invention were manufactured by pasting the surfaces.
The layer structure of the obtained packaging material was PET 12 μm / printing layer / anchor coating agent layer / polyethylene resin layer 15 μm / VMPET 12 μm / anchor coating agent layer / polyethylene resin layer 15 μm / low adsorbent sealant film 40 μm (outer layer 15.5 μm). / First low-adsorption resin layer 5 μm / anti-curl layer 7.5 μm / second low-adsorption resin layer 5 μm / inner layer 7 μm).

[Example 6]
A packaging material was produced in the same manner as in Example 5 except that the low adsorptive sealant film of Example 2 was used instead of the low adsorptive sealant film of Example 1.

[Example 7]
A packaging material was produced in the same manner as in Example 5 except that the low adsorptive sealant film of Example 3 was used instead of the low adsorptive sealant film of Example 1.

[Example 8]
A packaging material was produced in the same manner as in Example 5 except that the low adsorptive sealant film of Example 4 was used instead of the low adsorptive sealant film of Example 1.

[Comparative Example 1]
A low adsorptive sealant film was produced in the same manner as in Example 1 except that 100% by mass of COC (TOPAS 8007F-600) was used as the resin composition constituting the first and second low adsorptive resin layers. .
In the resulting low adsorptive sealant film, generation of fish eyes was observed.

[Comparative Example 2]
Example 1 except that a blend of 70% by mass of COC (TOPAS 8007F-600) and 30% by mass of LDPE (Suntech M6545) was used as the resin composition constituting the first and second low-adsorption resin layers. In the same manner as described above, a low adsorptive sealant film was produced.
The resulting low adsorptive sealant film was wrinkled.

[Comparative Example 3]
A packaging material was produced in the same manner as in Example 5 except that an LLDPE film (thickness: 40 μm) was used instead of the low adsorptive sealant film of Example 1.

[Comparative Example 4]
A packaging material was produced in the same manner as in Example 5 except that the low adsorptive sealant film of Comparative Example 1 was used instead of the low adsorptive sealant film of Example 1.

[Comparative Example 5]
A packaging material was produced in the same manner as in Example 5 except that the low adsorptive sealant film of Comparative Example 2 was used instead of the low adsorptive sealant film of Example 1.

[Comparative Example 6]
Using the resin and resin composition prepared in (1) to (3) of Example 1 and the three-layer coextrusion film forming method using the inflation method, the outer layer is 15.5 μm / the low adsorbent resin layer is 10 μm / the inner layer. Although a film (thickness 40 μm) having a layer configuration of 14.5 μm was produced, the film lacked flexibility and many wrinkles were generated, and a film that could withstand use as a sealant could not be formed.

[Evaluation methods and results]
(Appearance evaluation)
About the sealant film of Examples 1-4 and Comparative Examples 1-2, the presence or absence of fish eyes and wrinkles was confirmed. The results are shown in Table 1. In the table, the case where there is no fish eye or wrinkle is indicated by ◯, and the case where it is present is indicated by ×.

  In Comparative Example 1 in which the first and second low adsorptive resin layers were 100% by mass of COC, the appearance deteriorated due to fish eyes. Moreover, the comparative example 2 which contains 30 mass% of LDPE in the 1st and 2nd low adsorptive resin layer confirmed the wrinkles by film forming stability having deteriorated.

(Adsorption evaluation)
The packaging materials of Examples 5 to 8 and Comparative Example 3 were cut into 10 cm × 10 cm squares, and their initial weights were measured.
10 g of l-menthol solid (Pure Chemical Co., Ltd.) 10 g is put in a stainless steel container with a capacity of 10 liters, the container is covered with l-menthol vapor, and the laminated body cut out in the container is suspended. Stored at 7 ° C. for 7 days.
After storage, the laminate was taken out and weighed, and the amount of l-menthol adsorbed was calculated from the difference from the initial weight.

(Seal strength evaluation)
The laminates of Examples 5 to 8 and Comparative Example 3 were laminated with the sealant film inside, and heat sealer (TP-701S HEAT SEAL TESTER manufactured by Tester Sangyo Co., Ltd.) was used at 160 ° C. for 1 second, pressure 1 kgf / Heat sealed at cm ² .
Next, this was cut out into a strip shape having a width of 15 mm, and the sealed portion was peeled off using a Tensilon tensile tester (RTC-1310A manufactured by Orientec Co., Ltd.), and the seal strength was measured. The tensile speed at this time was 300 mm / min.
The results of adsorption evaluation and seal strength evaluation are shown in Table 2.

  Examples 5 to 8 showed high seal strength and low adsorptivity, but Comparative Example 3 adsorbed a large amount of l-menthol although the seal strength was high.

1. Outer layer 2. 1. First low-adsorption resin layer 3. Anti-curl layer Second low adsorptive resin layer5. Inner layer 10. Base material layer 11. Adhesive layer 12. Barrier layer 13. Adhesive layer 14. Sealant film

Claims (9)

A low-adsorption coextrusion multilayer sealant film having five layers of an outer layer, a first low-adsorption resin layer, an anti-curl layer, a second low-adsorption resin layer, and an inner layer in contact with the contents in this order. There,
The outer layer is a layer made of linear low density polyethylene or high pressure method low density polyethylene,
The anti-curl layer and the inner layer are layers composed of linear low density polyethylene,
The anti-curl layer has a thickness of 5 to 20 μm,
Each of the first and second low-adsorption resin layers has a thickness of 3 to 7 μm, and includes 80 to 97% by mass of a cyclic olefin copolymer and 3 to 20% by mass of a high-pressure method low-density polyethylene. A layer composed of a resin composition,
The high pressure method low density polyethylene has a melt flow rate at 190 ° C. of 10 to 80 g / 10 minutes,
The cyclic olefin copolymer is a copolymer obtained by copolymerizing 55 to 85% by mass of a norbornene monomer and 15 to 45% by mass of an α-olefin, and has a glass transition temperature of 100 ° C. or less .
The low adsorptive coextrusion multilayer sealant film. A low-adsorption coextrusion multilayer sealant film having five layers of an outer layer, a first low-adsorption resin layer, an anti-curl layer, a second low-adsorption resin layer, and an inner layer in contact with the contents in this order. There,
The outer layer is a layer made of linear low density polyethylene or high pressure method low density polyethylene,
The anti-curl layer is a layer made of linear low density polyethylene having a thickness of 5 to 20 μm,
The inner layer is a layer made of linear low density polyethylene containing an antiblocking agent,
Each of the first and second low-adsorption resin layers has a thickness of 3 to 7 μm, and includes 80 to 97% by mass of a cyclic olefin copolymer and 3 to 20% by mass of a high-pressure method low-density polyethylene. A layer composed of a resin composition,
The melt flow rate at 190 ° C. of the high pressure method low density polyethylene is 10 to 80 g / 10
Minutes,
The cyclic olefin copolymer is a copolymer obtained by copolymerizing 55 to 85% by mass of a norbornene monomer and 15 to 45% by mass of an α-olefin, and has a glass transition temperature of 100 ° C. or less .
The low adsorptive coextrusion multilayer sealant film.   The low thickness according to claim 1 or 2, wherein the total thickness of the first and second low adsorptive resin layers is in the range of 7 to 33% of the total thickness of the low adsorptive coextruded multilayer sealant film. Adsorbent coextruded multilayer sealant film. The low adsorptive coextruded multilayer sealant film according to any one of claims 1 to 3 , wherein the total thickness is 20 to 150 µm.   The low adsorptive coextrusion multilayer sealant film according to any one of claims 1 to 4, wherein the outer layer is a layer made of linear low density polyethylene. The low adsorptive coextrusion multilayer sealant film according to any one of claims 1 to 5, wherein the cyclic olefin copolymer has a glass transition temperature of 85 ° C or lower.   The packaging material formed by laminating | stacking a base material on the surface of the outer layer side of the low adsorptivity coextrusion multilayer sealant film of any one of Claims 1-6.   A packaging bag obtained by stacking and packaging the packaging material according to claim 7 so that the inner layer of the low-adsorption coextruded multilayer sealant film is a layer in contact with the contents.   A liquid paper container obtained by overlapping and packaging the packaging material according to claim 7 so that the inner layer of the low-adsorption coextrusion multilayer sealant film is a layer in contact with the contents.

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